This proposal seeks travel, registration and housing support for participants in the fourth in the series of bi-annual meetings on human gene therapy to be presented by the Cold Spring Harbor Laboratory. The meeting will take place from September 23-27, 1998. This is one of the major Cold Spring Harbor meetings and will bring together in the intensive and highly interactive style characteristic of Cold Spring Harbor meetings the basic scientists who are developing the tools for efficient, targeted and safe transfer of therapeutic genes in humans and clinicians who are characterizing and treating human disease. The meeting will be divided into 8 presentation sessions and three poster sessions. These sessions will emphasize issues of technology development rather than more immediate clinical application, and will cover many of the topics of current importance to the eventual development of clinically effective human gene therapy, including the design of efficient viral and non-viral gene transfer reagents, the characterization of transgene expression and its regulation, techniques for stable and efficient transplantation of genetically modified cells and the development and study of faithful animal disease models. To a lesser extent, we will include some discussion of existing and imminent human clinical studies to the extent that they indicate or illuminate questions of gene delivery and expression. Participation by younger, less well established investigators in the proposed meeting will continue to be emphasized at Cold Spring Harbor Laboratory meetings.